Auburn's Deer Lab Studies Collared Deer

By DAVID RAINER

Alabama Department of Conservation and Natural Resources

Ninety white-tailed deer are grazing and running around in various parts of Alabama with distinctive collars around their necks. Those collars come in two colors, orange and brown, and the difference in colors is extremely important.

DO NOT shoot the orange-collared deer, please. The deer with brown collars have no such restriction, according to Dr. Stephen Ditchkoff at Auburn University, which is conducting studies on the collared deer through its white-tailed deer research program.

Of those 90 collared deer, 30 are fitted with orange collars that provide GPS-tracking data and 60 have brown collars, which are VHF radio-equipped. So far, hunters have abided by the request that the orange-collared deer be spared.

“I’m not aware of any of our orange-collared deer being harvested,” Ditchkoff said. “And these (orange-collared) deer should not be harvested. In terms of research, it’s more sit-and-wait right now. We wanted them out during the hunting seasons.

The brown collars are designed to look at mortality rates. Some of the deer were collared about a year ago, while some have only had the collars for about two months.

“I have not had any calls from hunters that have harvested a deer with a brown collar either.”

The advice for a hunter who encounters a BROWN-collared deer is relatively simple.

“Shoot it if you would normally shoot it,” Ditchkoff said. “Pass it up if you would normally pass it up. We’re looking at mortality rates due to natural and human-induced causes.

“The orange-collared deer are to look at movement patterns. The collars send a location every hour, so we can track the deer in response to hunting pressure, how they cross property lines and get a feel for that as the season progresses.”

The deer were collared in four different areas in the state – Oakmulgee Wildlife Management Area (WMA), a 44,500-acre WMA in Bibb, Hale, Perry and Tuscaloosa counties; the 28,214-acre Barbour County WMA and two groups of private properties in Pickens and Marengo counties.

Ditchkoff said it will be another 16 months before all the data is collected from the collars and another four to six months to analyze the data and complete a report.

However, there is significant research at Auburn University’s Deer Lab, a 430-acre high-fence research facility in Camp Hill, Ala., for whitetails that has produced surprising results, some that may change the way deer herds are managed in Alabama.

“One of the major research thrusts has been to examine reproductive success and determine which males do most of the breeding,” Ditchkoff said. “Everybody has their own little pet theory as they’re sitting around the campfire – the one with the biggest antlers or the oldest buck. But what we’re finding is the most important factor in reproductive success is body size. Large antlers and increased age are important. Antler size, age and body size are all linked, but if there is one factor that is more important it’s body size. Larger-body deer did a higher percentage of breeding than smaller-body deer even if they are the same age or have the same antler size.”

But that does not mean that younger males are excluded from the breeding activity, Ditchkoff said.

“We’re also finding that all age classes are successful breeders, but the majority of the breeding tends to be from larger-body deer, which tend to be older deer.

“In populations dominated by young males from 1 1/2 to 2 1/2-year-olds, the 1 1/2s get a lot of breeding opportunities. In populations that have a lot of mature males, the 1 1/2s get very few breeding opportunities, yet they do get some.”

Another surprising discovery from the research facility is that buck fawns actually sire fawns in situations where younger males dominate the population. Ditchkoff said the herd’s doe-buck ratio is not as important as the age of the bucks in the breeding dynamic.

“The young males are so disorganized with their breeding, it’s a free-for-all,” he said. “Where there are mature males, more than 3 years old, they suppress the breeding of the younger males.”

Ditchkoff said in the first year of the breeding study there were two mature males at 3.5 years old in the study, and many of the younger males were involved in the breeding activity.

“When we started getting both 3 1/2s and 4 1/2s in the populations, we saw the breeding success from the younger males significantly decline,” he said.

Ditchkoff said more analysis is needed before any conclusions can be transferred to Alabama’s hunters and landowners.

“This is pretty much the first data of this kind to start to determine which males are actually doing the breeding,” he said. “Continued research is going to help elucidate the factors involved – how much more important is body size than antler size, how much more important is body size than age.

“In theory, it could have implications on selective harvest. You know, which male should you shoot. The second thing we’re finding is that when a male reaches 5 1/2 to 6 1/2, even though they grow larger antlers, they really don’t participate much in the breeding. They’ve done most of their breeding. That could have implications on how someone chooses to harvest their deer.”

Ditchkoff said the biggest impact on a deer herd comes from the practice of letting the younger bucks walk.

“If you get older males in your population, if you let your younger males age, you will have a streamlining of the process,” he said. “You will have higher-quality animals doing the breeding, which will help improve genetics in your herd, which is very important. The second benefit of having older males in the population is the fawning dates are compressed. The dates are earlier and shorter in duration. You will decrease fawn mortality and get greater fawn growth before winter, and you should have a more intense rut.”

Ditchkoff said letting the younger males walk not only improves antler size but also increases the “functionality” of the herd.

“Older males provide social stability,” he said. “Most does will be bred during the first estrus cycle. Our birthing period at our Auburn University research facility is 18 to 22 days. From all indications we’re not having late-born fawns.”

Ditchkoff said it’s still up to Alabama hunters and landowners to determine their preferred outcomes when it comes managing their deer herds.

“Obviously, don’t shoot small bucks if they want a more compressed rut, if they want that rut to be earlier in the season, if you want to have fewer late-born fawns. If they want to have deer with larger antlers, there’s a simple way to do it - shoot fewer younger bucks.

“But if that young buck puts a smile on their face, shoot it.”

Ditchkoff also thinks some people may have the wrong idea about culling deer from their herds. He said from 70 to 90 percent of bucks with a spike on one side or a deformed antler had sustained some type of injury or trauma to the pedicle (antler base).

“A lot of people are looking at 4-year-old deer that might have deformed antlers as a cull, and they want to remove it from the herd,” he said. “If the deer is going to put a smile on your face, shoot it. But if you’re removing it as a cull, I think you’re damaging your herd. By having mature bucks out there, they are providing social stability.”

PHOTOS: Auburn University’s Deer Lab team sedated and placed collars on 90 white-tailed deer in four areas in Alabama. Researchers ask that hunters DO NOT shoot the 30 deer that are fitted with orange collars equipped with GPS tracking devices. The 60 deer with brown collars are being used in a mortality study and do not have the no-shoot restrictions.